Mohamed Raissi, the brother of Lotfi Raissi, an Algerian-born pilot falsely accused of involvement in the September 11 terror attacks, has won an action for damages in the high court against the Metropolitan Police for wrongly arresting and holding him on suspicion of terrorist acts.

But Sonia Raissi, the wife of the pilot - who was the first person accused of participating in the attacks on the World Trade Centre and the Pentagon in 2001 - had a similar claim rejected yesterday.

The size of Mohamed Raissi's payout has yet to be determined, but he and his sister-in-law were each claiming £150,000. The Met was given permission to appeal against the judgment.

Mr Justice McCombe ruled that the police had no reasonable grounds for suspicion that Mohamed Raissi was involved in terrorist activities, just because he was close to his brother and lived near him and they had access to each other's houses in London. But his sister-in-law's case was different, and the factors the arresting officer had in mind "amply justified" the arrest at the time.

Both Mrs Raissi, 31, of Chiswick, west London, and her brother-in-law, of Heston, Hounslow, Middlesex, said their arrests by anti-terrorist police officers on September 21 2001 were unlawful and that they were falsely imprisoned.

Lotfi Raissi was arrested following an extradition request from the US. He was eventually released in February 2002 and a judge ruled that there was "no evidence" to suggest he was connected to 9/11 or any form of terrorism.

The French-born Mrs Raissi, who was working at Heathrow as a customer service agent at the time of her arrest, was released without charge after five days.

Mohamed Raissi, now 35, was detained for around 42 hours and also released without charge after being arrested at his home in Hounslow.

The judge said : "Mrs Sonia Raissi was not merely the wife of a prime suspect.

"She had been with him in a foreign country at a time when he might well have been thought to have been engaged, at the same time and at the same location, in the very training which was being undergone by one of the known perpetrators of the atrocities.

"It must have been reasonable to suspect that, if Lotfi was possibly involved, she too might be complicit in the offences."

Mohamed Raissi had been due to start work as a cleaning supervisor at Heathrow airport on the morning he was arrested, but the offer was withdrawn.

Lotfi Raissi, now 33, who spent nearly five months in jail following the false allegations, has an appeal pending against a ruling earlier this year that the home secretary was entitled to exclude him from a Home Office ex-gratia compensation scheme for victims of miscarriages of justice.